This invention relates in general to a regulating valve for a pressure fluid, and in particular to a pressure reducing valve of the type which has a valve body defining a bore, an inlet port and an outlet port communicating, in an axially spaced relationship, with the bore, and a sliding spool axially movable in the bore.
In a known pressure reducing valve of the aforedescribed type, the flange in the intermediate recess of the spool has the same outer diameter as the piston area at respective ends of the spool, and in the rest position of the spool the flange is located in the range of the inlet port at the high pressure side, whereas in the closing position of the spool it takes place at the level between the inlet port and the outlet port to close an opening in an inwardly projecting shoulder of the valve housing. The walls of the end portions of the spool facing the annular flange are perpendicular to the longitudinal axis of the sliding spool. The intermediate flange of the spool serves in this case for changing the cross section or closing a connecting bore in the valve housing (Zoebl, "Oel Hydraulik," Wien, Springer Verlag, 1963, p. 158).
The disadvantage of this prior-art solution lies in the fact that during its movement the sliding spool is subject to excessive axial forces exerted by the streaming pressure fluid.